1. Field of the Invention
The present invention relates to a mold pressing forming technology, and more particularly to a device and a method for forming a ceramic ferrule blank used in optical fiber communication.
2. Related Art
An optical fiber connector is an important device for optical fiber communication connection, and a ceramic ferrule is also a critical part in the optical fiber connector. A ceramic material has features of high strength, good corrosion resistance, good insulation performance, a smooth surface, and a long service life, and has become a best selection of the ferrule material in the optical fiber connector. Currently, in a device and a method for producing a ceramic ferrule blank, mainly a unidirectional positioning wet injection process is adopted. For example, PRC Patent Publication No. CN1376563A, entitled “Extrusion Forming Mold of Ceramic Ferrule Blank and Forming Technique”, disclosed a mold and a technique for manufacturing a zirconium dioxide optical fiber ferrule blank. An extrusion forming mold includes a case, a spiral feeder, a heater, a perforated board, an extrusion reducer pipe with a cooling device, a soft core needle support, and a core needle soft wire. In the forming technique, a raw material is fed from the spiral feeder. The raw material is pushed by a spiral axis, is heated and melted, and forms a melted high pressure fluid in the cavity after passing through the perforated board. The fluid is cooled and changes a size in the reducer pipe, forms a through-rod with an extremely high concentricity under an action of the core needle soft wire. Then, after a cutting process, a dewaxing process, a presintering process, and end processing, a ceramic ferrule blank is obtained. The device and the method for forming the ceramic ferrule blank mainly have the following defects. 1. During the process of forming the blank, the blank material enters the mold cavity of the mold from a material channel injection opening, and forms the blank after the extrusion process. The formed blank is an entirety having the residual raw material from the material channel injection opening, such that a great amount of precious raw materials are wasted in the forming process. 2. The injection process is a wet injection process, such that the blank is easily deformed when being formed. Further, the unidirectional positioning is adopted, such that during the forming process, an inner hole is easily blocked, and the inner hole at the non-positioning end may become eccentric, so as to affect a yield of the blank production. 3. A flowing property of the blank material must be considered when the injection process is adopted, so usually many additives must be added to the formed blank material, and thus, the blank after being sintered may have an uneven density, and is easily deformed. Further, the formed blank has the residual raw material from the material channel injection opening. Therefore, the subsequent finishing allowance is quite large, the working procedure is quite complicated, the production efficiency is low, and the production cost is high.